“Dear Evan Hansen,” the adaptation of the popular Broadway musical, has its heart in the right place and is a film with good intentions that wants to provide a voice for many of the problems facing teenagers today.

Even the best intentions go awry, which is the case with “Hansen.” It’s a flawed adaptation that struggles with a consistent tone and is hampered by a lead performance that grows increasing frustrating as the story progresses.

Ben Platt reprises his role from the Broadway musical, playing the title character – a high school senior with a severe social-anxiety disorder struggling to fit in.

At the suggestion of his therapist, Evan writes a letter of encouragement to himself, but the letter winds up in the hands of another classmate named Connor (Colton Ryan), adding to Evan’s anxiety.

Evan is convinced Connor is going to share the letter with everyone else, only to learn a few days later that his classmate committed suicide with his parents (Amy Adams and Danny Pino) convinced the letter was a suicide note left by their son. The parents want to learn more about their son, thinking that Evan was the only friend of their troubled teen.

Evan initially tries to tell them the truth but decides to go along with the lie to help the parents – and Connor’s sister (Kaitlyn Dever) – with their grief. But as the lie starts to grow, Evan finds himself learning more about himself and finally getting the life he thought was unattainable.

“Dear Evan Hansen” was directed by Stephen Chbosky, whose previous films “The Perks of Being a Wallflower” and “Wonder” dealt with some of the same themes. Chbosky tries to bring the same care to this film as he did in the other two films, but the addition of musical numbers leaves the tone off whack. It’s an ambitious movie that tries to do too much and can never quite find anything that it does very well.

Devers is fantastic as the grieving sister, providing the film’s best moments, while Adams and Julianne Moore – as Evan’s mom – do what they can with underwritten roles.

The biggest problem is Platt. Yes, this is a role he knows well from his Broadway days, and he really shines during the film’s musical numbers, but his presence undermines the rest of the film. He is the most out of place cinematic high school student since Stockard Channing in “Grease” – with the 27-year-old feeling awkwardly out of place in many of the film’s key moments.

It doesn’t help that the character isn’t very well written, with his actions making him harder and harder for the audience to like. By the time “Dear Evan Hansen” arrives at its conclusion, Evan’s transformation lacks authenticity – making this Broadway crowd-pleaser a film that loses its way in its transformation from stage to screen.

Starring: Ben Platt, Kaitlyn Dever

Directed by: Stephen Chbosky

Rating: PG-13 for thematic material involving suicide, brief strong language and some suggestive reference

Playing at: Regal Bowling Green Stadium 12, Regal Greenwood Mall Stadium 10, Highland Cinemas (Glasgow)

Grade: D+